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…/8, block_size, 8], [num_blocks, num_kv_heads, block_size/8, head_size, 8]
…ayout Updated `mha_batch_prefill` API and tests to support vLLM-style block tables alongside SGLang-style page tables, while enforcing the new hardware-optimized 5D vectorized KV cache layout. **Key Changes:** * **API**: Added `block_table` and `seqlen_k` arguments to python/C++ interfaces. * **Layout Enforcement**: Added strict checks for 5D vectorized KV layout (swizzled x=8) in host bindings and python wrappers. * **CodeGen**: Automatically select `VLLM_BLOCK_TABLE_2D` or `SGLANG_PAGE_TABLE_1D` trait based on input arguments. * **Tests**: Added `test_batch_prefill_vllm` to verify block table correctness and updated existing tests to use the vectorized layout.
poyenc
reviewed
Dec 31, 2025
…ensors in batch prefill - Enable 3D [N, H, D] K/V tensors for batch prefill, treating as linear layout with page_size=1. - Relax contiguity checks to only require the last dimension to be contiguous. - Update C++ stride calculations for 3D, 4D, and 5D layouts. - Add tests for 3D layout and non-contiguous KV cache.
valarLip
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Jan 13, 2026
zhuyuhua-v
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Jan 14, 2026
… in Batch Prefill kernel (#1754) * add page size 16 to test and op * add num_total_pages to kernel parameter * add is_sglang parameter * chang is_sglang to is_sglang_layout * kv last page size=16 pass * pass kv_last_page_lens to kernel * add parameters check before calling kernel * change kv layout to [page_num, page_size, nhead, hdim] * adopt the changes of struct fmha_fwd_batch_prefill_traits * change kv cache memory layout to [num_blocks, num_kv_heads, head_size/8, block_size, 8], [num_blocks, num_kv_heads, block_size/8, head_size, 8] * [FMHA] Integrate vLLM block table support and enforce vectorized KV layout Updated `mha_batch_prefill` API and tests to support vLLM-style block tables alongside SGLang-style page tables, while enforcing the new hardware-optimized 5D vectorized KV cache layout. **Key Changes:** * **API**: Added `block_table` and `seqlen_k` arguments to python/C++ interfaces. * **Layout Enforcement**: Added strict checks for 5D vectorized KV layout (swizzled x=8) in host bindings and python wrappers. * **CodeGen**: Automatically select `VLLM_BLOCK_TABLE_2D` or `SGLANG_PAGE_TABLE_1D` trait based on input arguments. * **Tests**: Added `test_batch_prefill_vllm` to verify block table correctness and updated existing tests to use the vectorized layout. * update CK * update ck * adopt api changes from fmha_batch_prefill_traits * add support for linear kv cache layout * update api * Refactor the test code by gathering the different test functions into one * update ck * update ck * Add profile measurements for batch prefill function * update ck * fix style * fix style * [FMHA] Support 3D linear layout (page_size=1) and non-contiguous KV tensors in batch prefill - Enable 3D [N, H, D] K/V tensors for batch prefill, treating as linear layout with page_size=1. - Relax contiguity checks to only require the last dimension to be contiguous. - Update C++ stride calculations for 3D, 4D, and 5D layouts. - Add tests for 3D layout and non-contiguous KV cache. * update ck --------- Co-authored-by: ltqin <letaoqin@amd.com>
yzhou103
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Jan 28, 2026
… in Batch Prefill kernel (#1754) * add page size 16 to test and op * add num_total_pages to kernel parameter * add is_sglang parameter * chang is_sglang to is_sglang_layout * kv last page size=16 pass * pass kv_last_page_lens to kernel * add parameters check before calling kernel * change kv layout to [page_num, page_size, nhead, hdim] * adopt the changes of struct fmha_fwd_batch_prefill_traits * change kv cache memory layout to [num_blocks, num_kv_heads, head_size/8, block_size, 8], [num_blocks, num_kv_heads, block_size/8, head_size, 8] * [FMHA] Integrate vLLM block table support and enforce vectorized KV layout Updated `mha_batch_prefill` API and tests to support vLLM-style block tables alongside SGLang-style page tables, while enforcing the new hardware-optimized 5D vectorized KV cache layout. **Key Changes:** * **API**: Added `block_table` and `seqlen_k` arguments to python/C++ interfaces. * **Layout Enforcement**: Added strict checks for 5D vectorized KV layout (swizzled x=8) in host bindings and python wrappers. * **CodeGen**: Automatically select `VLLM_BLOCK_TABLE_2D` or `SGLANG_PAGE_TABLE_1D` trait based on input arguments. * **Tests**: Added `test_batch_prefill_vllm` to verify block table correctness and updated existing tests to use the vectorized layout. * update CK * update ck * adopt api changes from fmha_batch_prefill_traits * add support for linear kv cache layout * update api * Refactor the test code by gathering the different test functions into one * update ck * update ck * Add profile measurements for batch prefill function * update ck * fix style * fix style * [FMHA] Support 3D linear layout (page_size=1) and non-contiguous KV tensors in batch prefill - Enable 3D [N, H, D] K/V tensors for batch prefill, treating as linear layout with page_size=1. - Relax contiguity checks to only require the last dimension to be contiguous. - Update C++ stride calculations for 3D, 4D, and 5D layouts. - Add tests for 3D layout and non-contiguous KV cache. * update ck --------- Co-authored-by: ltqin <letaoqin@amd.com>
valarLip
pushed a commit
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Mar 18, 2026
… in Batch Prefill kernel (#1754) * add page size 16 to test and op * add num_total_pages to kernel parameter * add is_sglang parameter * chang is_sglang to is_sglang_layout * kv last page size=16 pass * pass kv_last_page_lens to kernel * add parameters check before calling kernel * change kv layout to [page_num, page_size, nhead, hdim] * adopt the changes of struct fmha_fwd_batch_prefill_traits * change kv cache memory layout to [num_blocks, num_kv_heads, head_size/8, block_size, 8], [num_blocks, num_kv_heads, block_size/8, head_size, 8] * [FMHA] Integrate vLLM block table support and enforce vectorized KV layout Updated `mha_batch_prefill` API and tests to support vLLM-style block tables alongside SGLang-style page tables, while enforcing the new hardware-optimized 5D vectorized KV cache layout. **Key Changes:** * **API**: Added `block_table` and `seqlen_k` arguments to python/C++ interfaces. * **Layout Enforcement**: Added strict checks for 5D vectorized KV layout (swizzled x=8) in host bindings and python wrappers. * **CodeGen**: Automatically select `VLLM_BLOCK_TABLE_2D` or `SGLANG_PAGE_TABLE_1D` trait based on input arguments. * **Tests**: Added `test_batch_prefill_vllm` to verify block table correctness and updated existing tests to use the vectorized layout. * update CK * update ck * adopt api changes from fmha_batch_prefill_traits * add support for linear kv cache layout * update api * Refactor the test code by gathering the different test functions into one * update ck * update ck * Add profile measurements for batch prefill function * update ck * fix style * fix style * [FMHA] Support 3D linear layout (page_size=1) and non-contiguous KV tensors in batch prefill - Enable 3D [N, H, D] K/V tensors for batch prefill, treating as linear layout with page_size=1. - Relax contiguity checks to only require the last dimension to be contiguous. - Update C++ stride calculations for 3D, 4D, and 5D layouts. - Add tests for 3D layout and non-contiguous KV cache. * update ck --------- Co-authored-by: ltqin <letaoqin@amd.com>
valarLip
pushed a commit
that referenced
this pull request
Mar 18, 2026
… in Batch Prefill kernel (#1754) * add page size 16 to test and op * add num_total_pages to kernel parameter * add is_sglang parameter * chang is_sglang to is_sglang_layout * kv last page size=16 pass * pass kv_last_page_lens to kernel * add parameters check before calling kernel * change kv layout to [page_num, page_size, nhead, hdim] * adopt the changes of struct fmha_fwd_batch_prefill_traits * change kv cache memory layout to [num_blocks, num_kv_heads, head_size/8, block_size, 8], [num_blocks, num_kv_heads, block_size/8, head_size, 8] * [FMHA] Integrate vLLM block table support and enforce vectorized KV layout Updated `mha_batch_prefill` API and tests to support vLLM-style block tables alongside SGLang-style page tables, while enforcing the new hardware-optimized 5D vectorized KV cache layout. **Key Changes:** * **API**: Added `block_table` and `seqlen_k` arguments to python/C++ interfaces. * **Layout Enforcement**: Added strict checks for 5D vectorized KV layout (swizzled x=8) in host bindings and python wrappers. * **CodeGen**: Automatically select `VLLM_BLOCK_TABLE_2D` or `SGLANG_PAGE_TABLE_1D` trait based on input arguments. * **Tests**: Added `test_batch_prefill_vllm` to verify block table correctness and updated existing tests to use the vectorized layout. * update CK * update ck * adopt api changes from fmha_batch_prefill_traits * add support for linear kv cache layout * update api * Refactor the test code by gathering the different test functions into one * update ck * update ck * Add profile measurements for batch prefill function * update ck * fix style * fix style * [FMHA] Support 3D linear layout (page_size=1) and non-contiguous KV tensors in batch prefill - Enable 3D [N, H, D] K/V tensors for batch prefill, treating as linear layout with page_size=1. - Relax contiguity checks to only require the last dimension to be contiguous. - Update C++ stride calculations for 3D, 4D, and 5D layouts. - Add tests for 3D layout and non-contiguous KV cache. * update ck --------- Co-authored-by: ltqin <letaoqin@amd.com>
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Motivation
Introduces support for a vectorized KV cache memory layout (e.g., [num_blocks, num_kv_heads, head_size/8, block_size, 8]) to improve memory access efficiency and also support different type of block table such as vLLM and SGLang.
Technical Details
Key changes:
KV Cache Layout Optimization and Adjustment:
vLLM Block Table Integration:
Kernel Interface Updates:
Structure and Traits Updates:
Test Plan
Test Result
Submission Checklist